LOS ANGELES: Floyd Mayweather and Conor McGregor lit the touchpaper for their cross-combat superfight here Tuesday, turning the air blue in an expletive-laden face-to-face meeting to launch their global promotional tour for the bout.

More than 11,000 fans crowded into Los Angeles’s Staples Center for a raucous first live showdown between former boxing world champion Mayweather and Irishman McGregor, one of the biggest stars of mixed martial arts.

The two men are set to face each other in a boxing ring in Las Vegas on August 26 in what could be the richest fight in history after finally agreeing to climb into a boxing ring following a year-long guessing game over whether they would ever do battle.

The immaculately tailored profanity set the tone for a spectacle shot through with an endless torrent of abuse from both fighters, no doubt delighting promoters as they attempt to sell a fight for which ringside tickets will go on sale at around $10,000.

The suited McGregor was the first to take the microphone, mocking Mayweather’s decision to show up wearing a tracksuit, suggesting it was linked to the American’s reported tax difficulties.

“He’s in a tracksuit, he can’t even afford a suit anymore!” McGregor declared to roars of laughter from the massed ranks of his green-shirted fans crammed into the lower tiers of the famous basketball arena.

McGregor, who will start as an overwhelming underdog against one of the most accomplished defensive fighters in history, was bullish about his prospects of victory. “The 0 has got to go,” McGregor declared, referring to Mayweather’s perfect 49-0 record.

“I’m going to knock him out inside four rounds, mark my words,” McGregor said, to more roars.

A stony-faced Mayweather meanwhile bided his time before taking the microphone and unfurling his own cascade of expletives.

Mayweather meanwhile responded to the jibes about his finances – he recently filed for an extension to pay his 2015 tax bill – by producing an uncashed check for $100 million from an assistant’s rucksack.

McGregor was again ready with a riposte: “Give it to the taxman!”

Mayweather was unruffled however, vowing to administer a comprehensive victory over the 28-year-old Irishman despite being 40.

“I’m not the same fighter I was 10 years ago. Or 5 years ago. Or 2 years ago,” Mayweather said.

“But I’ve got enough to beat you. He can choose which way he wants to go. Either on his back or on his face.” --AFP